Cutting gathering device for a continuous mining machine



S. BOWMAN CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE Oct. 30, 1956 8 Sheets-Sheet 1 Filed Aug. 2'7, 1953 INVENTOIL SPENCER BOWMAN S. BOWMAN Oct. 30, 1956 CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE 8 Sheets-Sheet 2 Filed Aug.' 27, 1953 INVENTOR. SPENCER BOWMAN ATTORNEY Oct. 30, 1956 s. BOWMAN 2,768,728

CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE Filed Aug. 27, 1953 8 Sheets-Sheet 3 ATTORNEY S. BOWMAN Oct. 30, 1956 CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE 8 Sheets-Sheet 4 Filed Aug. 27, 1953 INVEN TOR. SPENCER BOWMAN S. BOWMAN Oct. 30, 1956 CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE 8 Sheets-Sheet 5 Filed Aug. 27, 1953 A WW VA Ni IN V EN TOR. I SPENCER BOWMAN A TTOR/VEY s. BOWMAN 2,768,728

CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE Oct. 30, 1956 8 Sheets-Sheet 6 Filed Aug. 27, 1953 mm NW E 0 a o" 5 C N M 8 A T TORNE Y S. BCWMAN Oct. 30, 1956 CUTTING GATHERING DEVICE FOR A CONTINUOUS MINING MACHINE 8 Sheets-Sheet 7 Filed Aug. 27, 1953 IN VEN TOR. SPENCER BOWMAN ATTORNEY Oct. 30, 1956 s, ow 2,768,728

CUTTING GATHERING DEVICE FOR AYCONTINUOUS MINING MACHINE Filed Aug. 27, 1953 v s Shet's-Sheet 8 W 85 as so FIG. 8

IN VEN TOR.

SPENCER I BOWMAN 6 ATTORNEY United States Patent CUTTING GATHERING DEVICE FOR A' CON- TINUOUS MINING MACHINE Spencer Bowman, Bay Village; Ohio, assigno'r, by mesne assignments, to Westinghouse Air Brake Company, a corporation of Pennsylvania Application August 27, 1953, SerialNo. 376,899

14 Claims. (Cl. 198- -8) This invent-ion relates broadly to continuousmining machines of the multiple rotor type, but more particularly to cutting or coal gathering devices therefor.

In continuous cult-ting and loading mining machines of the multiple cutting rotor type, it is usual to provide center-to-center adjustment of the rotors, or to provide means whereby the rotors can be extended laterally with the outboard ones projecting beyond the confines of the machine for cutting a width greater than the normalwidth of the machine. In orderto facilitate the removal of the machine from the race being mined, to reduce interference irom props and the like, as well as facilitatetramrning, the cutting rotors are made retractable within the confines of the machine.

Mining machines of this type are also usuallye'quipped with conveyors for removing the minedcoal from the bottom of the face. These conveyors generally lead from" the central front end of the machine, near the mine floor, rearwardly toward the other end. Since the rotors are arranged for cutting. a width greater than the width of the machine, it is necessary to provide means for gathering the mined coal from the ends of the cut to the conveyor. Obviously such device must be capable of reaching the ends or sides of the cut so that all loose coal can be removed as the cutting operation progresses; Com sequently the gathering device must be expandable be yond' the sides of the machine to reach the cuttings of the outboard rotors, and, like the rotors, must also be retractable.

The primary object of this invention is to provide such: a machine with a pair of gathering devices one' mounted on each side of the central conveyor, and capable of taking the cuttings within the full length of the out, even though it extends beyond the sides of the machine, the devices being retractable within the confines of the machine to facilitate tramrning operations and the like;

Another object of this invention is to produce cutting gathering devices, of the endless chaintype, equipped with scrapers, paddles or scoops operatively carried by its links.

Another object of this invention is to provide power actuated means, readily controllable, through which the" endless chain may be extended laterally of -themachine beyond the sides thereof for gathering operation of the cuttings within the entire length of the cut,- and retractable within theconfines of the machine.

Another object of this invention is to produce such anadjustable device, arranged anddisposed in a manner enabling its expansion and retraction to take place without affecting its operation and effectiveness.

Another object of this invention is to provide such gathering devices that are positive in operation, con venient in use", relatively simple and of general superiority and serviceability.

In the drawing which illustrates a preferred embodiment of the invention: I

Figure l is a top plan view of one of the gathering devices shown in extended operative position.

2,768,728 Patented Get. 30, 1956 Figs. 2, 3, and 4 are views similar to Figure 1, illustra-ting several positions which the gathering device assumes as it is retracted to the position shown in Figure 4.

Figure 5 is a side elevational view of the front endof a mining machine embodying the invention.

Figure 6 is an enlarged sectional view taken on line 6-6 in Figure 1.

Figure 7 is an enlarged sectional view taken on line 77 in Figure 1.

Figure 8 is an enlarged sectional view taken on line 8'8 in Figure 1'.

Figure" 9' is an enlargedsectional view taken on line 99 in Figure 1.

Figure 10 is a sectional view taken on line 1010 in Figure 1.

Figure 11 is an enlarged cross-sectional view taken on line 11 -11 in Figured Figure 1'2 is an enlargedsectional view taken on line 12 12111 Figure 1 and looking in the direction of the arrows.-

Figure 13 is an" enlarged top plan view of the bevel gear train shown inFigure 1.

Figure 14 is an enlarged side view of a portion of a chain used in the device.

Referring to the drawings, in which like symbols designate corresponding" parts throughout the several views, inorder t-o facilitate-the understanding of [the construction about to be described;- it might be well to mention that the drawings, especially Figures 1 to 4 inclusive, show" only the lower front right hand side of the mining machine embodying the invention. It is to be understood that in practice the'mining machine is equipped with two gathering devices extending laterally in opposite directions from a central conveyor A, the right hand gatheringdevicegenerally designated by B, being shown in Figures to 4; while the left hand device, which is a replica of- B, is not shown. It is also to be understood that each'gatheriugdevi'c'e is mounted on a rigid base plate C which, asshown in Figure 5, extends forwardly' from the main frame D of thernachine with its front end close to the floor of the mine. Each plate C has its inner endpivotal-ly connected to the main frame D by cross pins 20 and 21. From pin 21 extends an offset arm 22, Figure 5", connected to two hydraulic jacks 23, through which the front or free end of the plate C can be raised or lowered with respect to the mine floor 24 by pivotal movement of the plate on the axes of the pinsZti and 21.

A power shaft 25 extends through the tubular pin 26, and hasfixed on one end thereof a sprocket wheel 26, which, in practice; is connected to a source of rotary power sueh'as a motor by a chain, not shown. The other end of' the shaft 25- extends into a gear box 27, where it is journaled' within a ball bearing 28, and has mountedthereon a bevel gear 29;. Figure 13. A sec- 0nd bevel; gear- 30 in mesh with the" gear 29, is fixed on one end of a splined shaft 31: mounted at right angles with thenshaft 25 and also journaled within a ball bearing 32. As shown in' Figure 7, the other end portio-n'of the splined shaft 31 extends through a gear box 33 where it is fitted with packing members 34 through which the shaft is treeto'slide. Cut in the shafit there are two longitudinally extending straight grooves 35 hav-' ingfitted therein the keys of a bevel gear 36 mounted'on the shaft for rotation therewith but slidable relative thereto. The gear is in-the box 33 and has a shank 37 journ-aled ina bearing fixed in the wall of the box. The upper endof the gear box 33 is formed with an annular flange 38 clamped to the underside of a carrier 40 by two half rings 41. Carrier 40, which. is elongated, substantially flat and relatively thin, is preferably made of two parallel plates 42 and 43 spaced by posts 44 and 3 clamped together by bolts 45 as clearly shown in Figure it The plates 42 and 43 are shaped so that when clamped together they form around the major pontion of the carrier 48 a chain guideway or track 46.

As shown in Figures 6 and 7, the bevel gear 36 is in mesh with another bevel gear 47 mounted on a stub arbor 48, which arbor extends through the carrier 40 where it is journaled in spaced bearings 49. Between the bearings 49, arbor 48 is provided with integral gear teeth forming the sun gear 50 of the planetary gear train shown in Figure 11, which includes three planet gears 51 mounted between the plates 42 and 43 of the carrier 40 on arbors 52, and in mesh with a floating ring gear 53 axially retained between the plates of the carrier 40. The outside of the ring gear 53 forms a sprocket wheel 54 extending peripherally into the guide-way 46 of the carrier 40.

Underneath the sprocket wheel 54, the base plate C is provided with a rectangular longitudinally extending opening 55, Figure 1, having the long sides thereof forming inverted V-shaped guides 56, Figure 6, over which are fitted for slidable movement thereon corresponding but shorter guide-ways 57 forming a part of the gear box 33. Between the guides 56, the gear box 33 has two spaced depending lugs 58 having pivotally connected thereto by a cross pin 59 the apertured terminal of a piston rod 6 This rod extends from a hydraulically operated piston, not shown, mounted within a cylinder 61, which cylinder has its outer end pivotally connected to the frame D by a cross pin 62, Hydraulic fluid may be supplied to the cylinder 61 through conduits 63. It will thus be understood that the gear box 33, together with the sprocket wheel 54 and the portion of the carrier 40 adjacent thereto, can slide on the straight guides or tracks 56, which slidable movement may be effected through the hydraulic jack 60-61.

Mounted within the ends of the carrier 40 opposite the sprocket wheel 54 and between the plates 42 and 43, there is a second sprocket wheel 64 peripherally extending into the guide-way 46. As shown in Fig. 6, this last sprocket wheel is rotatably mounted on an eccentric portion 65 of a stub arbor 66 which extends through the adjacent end of the carrier 40. As the arbor is turned. the position of the sprocket wheel is changed to adjust the tension of an endless chain carried thereby and about to be described. The arbor 66 may be fixed in any desired position by two bolts 67 screwed in the carrier, and extending through corresponding holes 68 provided through the annular flange of a bushing 69 fixed to the arbor by a key 70.

As seen in Figures 1 to 4, the carrier 40 adjacent the sprocket wheels 54 and 64, has partly circular ends united by a straight side 71 and by two other straight sides 72 and 73 forming between them an obtuse angle. The guide-way or track 46 extends within the circular ends, straight sides 71 and 72, but not within the side 73.

The front left corner of the base plate C has a hole extending therethrough. Figure 7, in which is piloted a block 75 held on the plate by one or more bolts 76. A stub arbor 77 extends through the block 75, and has rotatably mounted thereon a third sprocket wheel 78, which is fitted within the slotted or bifurcated end 79 of a back up arm 80. A dust protecting lid 81 is fixed to the block 75 by any suitable means, and extends partly over the carrier 40. As clearly shown in Figure 7, block 75 and lid 81 also form a guide-way 46', which when the carrier 40 is in the operative position shown in Figure 1, constitutes a continuation of the guide-way 46 around the sprocket wheel 78. The back up arm 80 has a straight portion 82 extending into the bottom of the guide-way 46', and a lug 83 extending inwardly therefrom to end between the plates 42 and 43 of the carrier 40 where it carries a cross pin 84, which pin extends through a cam slot 85 provided through both plates 42 and 43. In ad 4 dition to the slot 85, the bottom plate is formed with another arcuated cam slot 86 through which extends a post 87 fixed to the base plate C as shown in Figure 8.

A plate-like arm 88 mounted between carrier 40 and base plate C, has one end pivotally connected to the base plate by a pin 89, while the other end carries an upright arbor 90 which extends through a slot 58 formed through the lower plate 43 of the carrier. On the arbor 90, there is a fourth sprocket wheel 91, which normally extends into the guide-way 46 of the straight side 71 of the carrier. This arm has an elbow engageable with a stop pin 92 for limiting its pivotal movement in one direction. An endless chain 93 is drawn tightly over the three sprocket wheels 54, 74 and 78, for traveling motion in a single plane within the guide-ways 46 and 46'. In normal operating position as shown in Figure l, the sprocket 91, while in mesh with chain 93, performs no supporting function. In practice, chain 93 is preferably equipped with cutting raking means such as suitable paddles 94 shown in Figure 14, and if desired may also be equipped with adequate cutters for cutting the lower trusses usually remaining between the circular cuts of the rotors.

During the mining operation, both gathering devices are extended to the position shown in Figure 1, and each chain 93 between the sprocket wheels 64 and 78, made to travel toward the conveyor A. Traveling motion of the chain is of course obtained by rotary power applied to the sprocket wheel 26 and transmitted to the driving sprocket wheel 54 through shafts 25 and 31, bevel gears 36 and 47, and the planetary gear train shown in Figure 11. Since the chains of both devices must travel in opposite directions, it is obvious that rotary power is also applied to each device in opposite directions. As the chain or flexible member 93 travels over its supporting elements or sprockets 54, 64 and 78, the chains paddles 94, from the sprocket 64 to the sprocket 78 will rake or gather the coal, cut by the mining machine, toward the intake end of the conveyor A to be carried thereby away from the face being mined. As the gathering of cuttings takes place from the sprocket 64 to the sprocket 78, it will be understood that the chain 93 carries its greatest load as it reaches the sprocket 78. To prevent excessive chain stretch by this concentrated load, there is provided the back up arm which has a straight portion 82 extending from the sprocket 78 toward the sprocket 64 within the guide-way 46', and on which the chain is free to ride. In this extended or operative position of the device, the location of the back up arm 80, and more particularly of its straight portion 82 relative to the bottom of the guide-way 46', is controlled by the cross pin 84 engaging one end of the arcuated cam slots 85. The operative position of the carrier 40 relative to the base plate C is the result of the piston rod 60 at one end of its outward travel in the cylinder 61, which determines the location of the end of the carrier adjacent the sprocket wheel 54, while the location of the other end of the carrier adjacent the sprocket wheel 64 is controlled by the post 87 engaging one end of the cam slot 86. Obviously the chain 93, because of the position of the sprocket wheels and guide-ways 46 and 46', is limited to travel within a single plane which is substantially parallel to the upper face of the base plate C. The travel of the chain is limited to a path which, as shown in Figure 1, extends laterally well outside of the confines of the base plate, with the two front sprockets 64 and 78 widely spaced from each other.

When the cutting rotors of the mining machine are either partly retracted to reduce the length of the cut or entirely retracted within the confines of the machine to facilitate tramming operation or the like, it is necessary that the gathering devices be retracted accordingly. However, since they must remain operative at least when partly retracted to remove coal mined from a shorter cut, it is necessary that during the retracting operation of the devices, each chain 93 remains substantially tight 5. over its supporting sprocket wheels. To effect retraction of the device, the piston rod 60 is retracted hydraulically into the cylinder 61; thereby causing inward slidable movement of the gear box 33 on the straight guides 56, and consequently the slidable movement of the sprocket 54, and portion of the carrier 40 adjacent thereto, in a straight path parallel to the guides 56. Concurrently, rotation may still be imparted to the driving sprocket wheel 54 for effecting travelling motion of the chain 93 by Virtue of the slidable operative engagement of the bevel gear 36 on the shaft 31. During the initial retracting movement of the device as shown in Figure 2, the cam slot 86 moving relative to the post 87, causes inward pivotal movement of the carrier 40 and the lateral movement of the sprocket wheel 64 toward the wheel 78. Concurrently the cross pin 84 of the back up arm 80, riding within the cam slots 85, causes gradual removal of the back up arm away from the chain 93 to make room for the approaching sprocket wheel 64.

After the plate-like arm 88 carrying the fourth sprocket wheel 91, reaches the stop pin 92 as shown in Figure 3, the arm and fourth wheel travel with the sprocket wheel 54 on a straight path parallel to that of the wheel 54, thereby causing fourth wheel 91 to leave the guideway 46 while maintaining the chain substantially tight over its supporting wheels.

As the piston rod 60 reaches the end of its inward stroke, the gathering device is entirely retracted laterally within the confines of the base plate C as clearly shown in Figure 4, with the path of the chain changed froma triangular figure as shown in Figure 1, to a quadrilateral one as shown in Figure 4. During the entire retracting motion of the device, the chain 93, by virtue of the movement of its supporting elements or sprocket wheels to different locations, remains operatively tight, and if desired can be made to travel over its supporting elements to gather coal between the sprockets 64 and 77. As shown in Figure 4, the back up arm 80 has been moved inwardly between the plates 42 and 43 of the carrier to make room for the sprocket 64, which, together with the adjacent portion of the carrier 40, has moved more deeply under the stationary lid 81', while the post 87 has reached the other end of the slot 86.

When it is desired to again extend the device laterally to the Figure 1 position, the piston rod 60 may again be moved outwardly from its cylinder 61, thereby causing the above described motion of the several parts to take place in reversed order.

The details of the structure and arrangement of parts shown and described may be variously changed and modified without departing from the spirit and scope of the invention.

I claim:

1. A cutting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, a carrier movably supported on said plate, a plurality of rotary elements mounted one on said plate and the others on said carrier, anendless flexible member closely drawn over said elements, means imparting travelling motion to said member in one direction over said elements, cutting raking means fixed to said member for travelling motion therewith, means effecting movement of said carrier relative to said plate to position the wheels carried thereby to different locations for changing the path of said member from one extending laterally outside of said plate to one substantially within the confines of said plate, and track means between said plate and carrier limiting movement of the latter through a path causing said member to remain closely drawn over said elements during said movement of the carrier.

2. A cutting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, a carrier movably supported on said plate, a plurality of rotary elements mounted one on said plate and the others on said carrier, an endless flexible meniber closely drawn over said elements, means imparting travellingmotion to said member in one direction over said elements, cutting raking means fixed to saidmember for travelling motion therewith, means effecting movement of said carrier to position one of said elements laterally outside or inside of the confines of said plate, and guiding means between said plate and carrier limiting movement of the latter through a path causing said member to remain closely drawn over said elements irrespective of said movement.

3. A cutting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, a carrier movably supported on said plate, a plurality of sprocket wheels including two side by side forward ones carried one by said plate and the other by said carrier, an endless chain closely drawn over all of said wheels, means imparting rotary motion to one of said wheels and travelling motion to said chain, means effecting movement of said carrier to vary the distance between said two forward wheels, and guiding means for said carrier limiting its movement through a path causing said chain to remain closely drawn over all of said wheels irrespective of said movement.

4. A cutting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, an elongated carrier movably supported on said plate, a plurality of rotatably mounted sprocket wheels including one on said plate and one on each end of said carrier, an endless chain closely drawn over said wheels, means imparting rotary motion to one of said wheels and travelling motion to said chain, straight track means between said plate and carrier to limit movement of one end of the carrier longitudinally of said plate, arcu ated track means between said plate and carrier to limit movement of the other end of the carrier transversally of said plate, and means connected to said carrier near one end thereof to effect said movements.

5. A cutting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, a plate-like elongated carrier movably supported by said plate on the upper side thereof, a plurality of rotatably mounted sprocket wheels including one on said plate and one on each end of said carrier, an endless chain closely drawn over said wheels, means adapted to impart rotary motion on one of the wheels on said carrier and travelling motion to said chain, cutting raking means fixed to said chain for travelling motion there with, guide-way means for said chain partly around said carrier, a pair of different track means between said plate and carrier limiting movement of one end of said carrier longitudinally of said plate and movement of the other. end of said carrier transversally of said plate, and means connected to said carrier near one end thereof to effect said movements.

6. A'cut'ting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, a carrier movably supported on said plate, a plurality of sprocket wheels .including two side by side forward ones carried one by said plate and the other by said carrier and two rearward ones carried by said carrier, means imparting rotary motion to one of said rearward Wheels and travelling motion to said chain, means effecting movement of said carrier to vary the distance between said wheels, and guiding means for said carrier limiting its movement through a path causing said chain to remain closely drawn over all of said wheels irrespective of said movement.

7. A cutting gathering device for a mining machine comprising a base plate, an endless flexible member adapted to travel laterally of the forward end of said machine, means carried by said plate supporting said member .in a taut condition capable of movement to vary the length of said travel, means imparting travelling motion to said member, cutting raking means mounted on said member for travelling motion therewith, means effecting movement of said supporting means, and cooperating guiding means on said plate and supporting means restraining said movement through a path causing said member to remain in said taut condition during variation of the length of it travel laterally of said machine.

8. The combination of a mining machine comprising a frame and a central conveyor operatively carried by said frame having its intake end forwardly of said frame, with a cutting gathering device comprising a pair of endless flexible members carried by said frame one on each side of said conveyor for travel laterally of the intake end thereof, means supporting said members in a taut condition, said supporting means including carriers movable on said frame to extend the travel of said members laterally outside or restrict it laterally inside the confine of said frame, means imparting travelling motion to said members toward said conveyor, cutting raking means mounted on said members for travelling motion therewith, means effecting movement of said carriers, and cooperat- .ing guiding means on said frame and carriers restraining said movement through a path causing said members to remain in said taut condition during said movement.

9. A cutting gathering device for a mining machine, comprising a base plate extending forwardly of the machine, a carrier movably supported by said plate, a plurality of sprocket wheels including two longitudinally forward and laterally inner and outer ones, the inner one carried by said plate and the outer one by said carrier, an endless chain closely drawn over all of said wheels having a working span extending between said inner and outer ones, means imparting rotary motion to one of said wheels and travelling motion to said chain in a direction of its working span toward said inner wheel, means effecting movement of said carrier to vary the distance between said inner and outer wheels, back up means for the Working span of said chain adjacent said inner wheel, mean automatically withdrawing said back up means from said working span upon reduction of the distance between said inner and outer wheels, and guiding means for said carrier limiting its movement through a path causing said chain to remain closely drawn over all of said wheels irrespective of said movement.

10. A cutting gathering device for a mining machine comprising an endless flexible member carried by said machine for travel within a triangular path and having a working span extending laterally of the longitudinal center axis of said machine, means supporting said member in a taut condition capable of movement to change the travel of said member to a quadrilateral path, means imparting travelling motion to said member in a direction of its Working span toward said center axis, cutting raking means mounted on said member for travelling motion therewith, means effecting movement of said supporting means, and means restraining said movement through a path causing said member to remain in said taut condition irrespective of said movement.

11. In a device of the class described, a set of four supporting elements mounted for rotation on their own axes, an endless flexible work performing member drawn closely over said elements, said member adapted to perform work during its travel from one of said elements to another, the length of said travel being normally greater than the distance between any other two of said elements, means for imparting travelling motion to said member over said elements, means enabling movement of three of said elements to different locations relative to the fourth one to vary the length of said travel, means effecting said movement, and means limiting movement of said three elements through a path causing said member to remain closely drawn over said elements irrespective of said movemeat.

12. In a device of the class described, a first supporting clement mounted for rotation on a fixed axis, a driving and other supporting elements mounted for rotation on movable arbors, an endless flexible member drawn closely over all of said elements, means for imparting rotation to said driving element and travelling motion of said flexible member over said elements, means enabling movement of said driving and other elements to different locations to vary the path of said flexible member, means effecting said movement, and means limiting said movement to a path causing said flexible member to remain closely drawn over all of said elements irrespective of said movement.

13. In a device of the class described, a first supporting element mounted for rotation on a' fixed axis, a driving and other supporting elements mounted for rotation on movable arbors, an endless flexible member drawn closely over all of said elements, mean enabling movement of said driving and other elements to different locations to vary the path of said flexible member, means effecting said movement, means for imparting rotation to said driving element and travelling motion of said flexible member over said elements concurrently with said movement, and means limiting said movement to a path causing said flexible member to remain closely drawn over all of said elements irrespective of said movement.

14. In a device of the character described, a support and a carrier movably mounted thereon, an endless flexible member, a first supporting element for said member rotatable on an arbor fixed on said support, a plurality of other rotating supporting elements for said member mounted on said carrier and capable upon movement of the carrier to assume different locations relative to said first element, the perimeter around all of said elements being substantially equal to the length of said member, means imparting travelling motion of said member around said elements, means effecting movement of said carrier into different locations of said other elements to vary the path of said member, and cooperating mean on said support and carrier restraining said movement through a path causing said perimeter to remain substantially constant.

References Cited in the file of this patent UNITED STATES PATENTS 1,303,797 Holmes May 13, 1919 1,489,600 Joy Apr. 8, 1924 2,106,918 Perazzoli Feb. 1, 1938 

